A large percentage of tires in use today require internal inflation pressure to support load. Tires used on automobiles, trucks, tractors, earthmovers, airplanes, and many other vehicles employ internal air pressure to carry load. Ever since the invention of the pneumatic tire internal air pressure contained within a tire structure has been the most efficient way to support a load and deliver performance expected from a tire.
Although slow speed, high load carrying vehicles like forklifts commonly use solid tires, these tires are not acceptable for most higher speed applications because of heat build up causing durability problems, harsh ride and poor traction due to small foot print on the road.
Most tires today are made from rubber which is highly hysteretic. When rubber is repeatedly flexed its temperature increases. It is common for a pneumatic rubber tire to warm up 20 degrees Fahrenheit above ambient during normal service. Most rubber automobile tires warm up at least 50 degrees Fahrenheit above ambient during high load Department of Transportation laboratory tests.
Some tires today are designed to normally run inflated but if air loss occurs they can run a short distance of 50 to 100 miles without air. These rubber run flat tires can heat up more than 150 degrees Fahrenheit above ambient during operation without air. Heat buildup is usually the limiting factor for run flat tire durability.
New materials, like polyurethane, with lower hysterisis then rubber are now being used in a small percentage of tires usually for low speed applications.